Industrial system and process utilizing turbo-compressor unit



Aug. 27, 1968 J. 5. HUCKS. JR 3,398,534

INDUSTRIAL SYSTEM AND PROCESS UTILIZING TURBOCOMPRESSOR UNIT Filed Nov. 18, 1966 INVENTOR JOSEPH S. HUCKSJ'r.

ATTORNEY United States Patent 3,398,534 INDUSTRIAL SYSTEM AND PROCESS UTILIZING TURBO-COMPRESSOR UNIT Joseph S. Hucks, Jr., West Hartford, Conn., assignor to Combustion Engineering, Inc., Windsor, Conn., a corporation of Delaware Filed Nov. 18, 1966, Ser. No. 595,389 8 Claims. (Cl. 6095) ABSTRACT OF THE DISCLOSURE An apparatus is associated with an industrial process which utilizes large quantities of gas compressed to a high pressure. There is provided a turbo-compressor unit driven by steam from a steam generator that may receive its heat input from a portion of the process, with this unit producing the compressed gas used in the process. The turbine has associated with it a condenser and the compressor has an intercooler. The improvement of the invention involves the method and apparatus whereby the cooling water from the condenser is conveyed through the intercooler and the condensate from the condenser is also conveyed through the intercooler but maintained separate from the condenser water. This condensate is then conveyed to the steam generator as the feed therefor. A refinement in the organization and process involves regulatingly bypassing a portion of the condenser water around the intercooler in response to the temperature of the condensate conveyed from the intercooler.

Brief description of the invention In industrial processes, such as the basic oxygen steel making porcess and the process for the production of ammonia whereby oxygen and nitrogen are combined in a reactor, large quantities of heat 'are evolved and large quantities of high pressure gas are utilized. Accordingly, systems have been proposed for generating this high pressure gas by utilizing the steam that is produced in a waste heat boiler which employs as its heating medium the hot gases evolved from the process. The present invention is directed to such an improved system and method wherein high efiiciency is obtained with optimum heat recovery. In a known manner the steam is conveyed to the turbine of the system which, in turn, drives the gas compressor. The exhaust from the turbine is condensed in a suitable condenser, and the compressor has associated with it a cooling device in order to cool the compressed gases. The condensate produced in the condenser is conveyed through this cooling device to act as a portion of the cooling medium therefor. However, this condensate is not sufiicient to provide the necessary cooling and thus, in addition but separate from the condensate, the cooling water after passing through the condenser is directed through this cooling device. There is provided a temperature responsive device sensing the temperature of the condensate egressing from the cooling device and a control is provided to regulate the amount of cooling fluid that bypasses the cooling device through a suitable conduit connected in bypass relation with this device. Through this system the maximum heat input to the condensate can be provided and maintained over reasonable limits thereby obtaining maximum heat recovery and at the same time adequate cooling of the compressed gas is provided.

Description of the drawing The single figure is a diagrammatic representation of a system employing the improvement of the invention and operative to carry out the process of the invention.

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Detailed description Referring now to the drawing wherein like reference characters are used throughout to designate like elements, the illustrative and preferred embodiment of the invention depicted therein includes means 10 for carrying out 'an industrial process with there being specifically illustrated here a basic oxygen steel making furnace. The exhaust gases from this furnace 10 are conveyed through a suitable hood diagrammatically shown at 12 which has associated with it a waste heat boiler with the tubes of this boiler lining the hood. The steam and water drum 14 forms a portion of this boiler, and steam from this drum is conveyed via conduit 16 to the accumulator 18. The accumulator is necessary since the steel making process is intermittent providing intermittent steam generation. Steam is conveyed to the turbine 20 either directly from line 16 or through line 20 connected with the accumulator. The turbine 20 forms part of a turbo-compressor unit which includes the compressor stages 22 and 24. The system shown is operated on the saturation steam cycle, however a superheated cycle may be used, and the exhaust from turbine 20 is conveyed to the condenser 26. The compressor has associated with it a cooling device identified as intercooler 28; and this intercooler is effective to cool the compressed gas (which maybe either air, oxygen enriched air or oxygen) intermediate the stages 22 and 24, and it also may be efiective to cool portions of the compressor. The compressed gas from compressor stage 24 may pass through additioinal apparatus 25 and then be introduced into the furnace 10. Illustrative of this additional apparatus the gas egressing from the compressor stage 24 may be air, and this apparatus may be the distillation apparatus for separating oxygen from the nitrogen in the air with the oxygen being introduced into the furnace 10.

The cooling medium for the intercooler 28 comprises both the condensate from condenser 26 and the cooling water utilized by this condenser. This cooling Water is conveyed from a suitable source such as a river 29 via pump 30 through the condenser 26 and then via conduit 32 through one section of the intercooler 28. The condensate is conveyed from the condenser 26 through conduit 34 and condensate pump 36 and conduit 38 through another portion of the intercooler 28. The intercooler is partitioned so that these two cooling fluids do not intermix but the compressed gases flow in indirect heat exchange relation with both of the fluids passing through the intercooler. The condensate egressing from intercooler 28 is conveyed via conduit 40 and by means of the feedpump 42 to the steam and water drum 14 of the waste heat boiler. In order to provide for optimum heat recovery and to desirably regulate the temperature of the feedwater, the temperature of the condensate egressing from intercooler 28 is controlled with there being provided for this purpose a bypass conduit 44 disposed around the intercooler 28 for bypassing a portion of the condenser cooling water around this intercooler. Placed within this bypass is the control valve 46, and this valve is regulated by the temperature responsive device 48 responsive to the temperature of the condensate egressing from the intercooler. Through this control arrangement the temperature of this condensate may be regulated Within reasonable limits.

It is necessary to utilize both the condensate and the condenser cooling water as cooling medium for the compressor since the condensate by itself would be quite insufiicient to provide the desired cooling. -By utilizing the condenser water after it is passed through the condenser as cooling medium for the intercooler, a minimum of additional equipment is necessary since the same pump used to pump the cooling water through the condenser is 3 effective to pump this water through the intercooler. It will only be necessary to slightly increase the size of this pump 'and then provide the necessary piping to convey the water through the intercooler.

Accordingly with the invention a highly eflicient system and process is provided with high heat recovery being obtained.

While I have illustrated and described a preferred embodiment of my inveniton it is to be understood that such is merely illustrative and not restrictive and that variations and modifications may be made therein Without departing from the spirit and scope of the invention. I therefore do not wish to be limited to the precise details set forth but desire to avail myself of such changes as fall within the purview of my invention.

What I claim is:

1. In a system having a steam generator, a condensing turbine operated by steam from said generator, a condenser receiving exhaust steam from said turbine and condensing the same and provided with means supplying cooling fluid to the condenser, means supplying condensate produced in the condenser as feedwater for the steam generator, compressor means driven by said turbine and including an intercooler, the improvement comprising'means directing at least a portion of the cooling fluid from the condenser through a first portion of said intercooler and means directing the condensate from said condenser through a second and separate portion of said intercooler and thence to the steam generating means.

2. The organization of claim 1 including a bypass for said cooling fluid around said intercooler and valve means in said bypass to control the flow therethrough.

3. The organization of claim 2 including means responsive to the temperature of the condensate egressing from said intercooler and eflective to control said valve means in said bypass to regulate, within limits, this temperature of the condensate.

4. In a system for a steel making process employing compressed gas and generating heat, a portion of which is utilized in a steam generator and wherein there is provided a steam turbine driven compressor for producing said high pressure gas and which is driven from the steam thus produced with there being a condenser for the exhaust of the turbine and with there being an intercooler means associated with the compressor, the improvement comprising means for directing a cooling fluid through the condenser and then through said intercooler, means for directing condensate from the condenser through said intercooler while maintaining it separate from said coolant, means for bypassing said intercooler means with a portion of said coo'lant, means for controlling the portion of the coolant thus bypassed in response to the temperature of the condensate egressing from said coolant.

5. In a process-wherein high pressure gas is utilized and heat is evolved, in which a portion of the heat is employed to generate steam with the steam being used to operate a turbine and compressor unit with the exhaust from the turbine being condensed by means of a cooling fluid and with the condensate being conveyed in heat exchange relation with compressed gas from the compressor, the improved operation comprising directing the cooling fluid after condensing the exhaust from said turbine into heat exchange relation with said compressed gas separate from said condensate.

6. The process of claim 5 including sensing the temperature of the condensate after it has been utilized to cool said compressed gas and regulatingly bypassing a portion of said cooling fluid from heat exchange relation with said compressed gas so as to, within limits, regulate said temperature.

7. In a basic oxygen steel making system wherein compressed gas is utilized and steam is produced fromthe heat generated and wherein the compressed gas is produced by a turbine and compressor unit driven by this steam and with the compressor having an intercooler and the exhaust from the turbine being condensed in a con denser, the improved method of operation comprising directing a cooling medium through the condenser and thence through the intercooler and directing the condensate from the condenser through the intercooler separately from the cooling medium and thence to a steam generator.

8. The process of claim 7 including bypassing the intercooler With a portion of the cooling medium and regulating the portion thus bypassed in response to the temperature of the condensate egressing from the intercooler to regulate, within limits, this temperature.

References Cited UNITED STATES PATENTS 5/1961 Furreboe 60-95 X 3/1965 Kemmetmuller 60-95 X 

